STREPTAVIDIN BINDING OBSERVED WITH AN ATOMIC FORCE MICROSCOPE
STREPTAVIDIN BINDING OBSERVED WITH AN ATOMIC FORCE MICROSCOPE
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DOI：
10.1016/0304-3991(92)90413-e
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发表时间：
1992-07-01
期刊：
影响因子：
2.2
通讯作者：
HANSMA, PK
中科院分区：
文献类型：
--
作者：
WEISENHORN, AL;SCHMITT, FJ;HANSMA, PK
原子力显微镜（AFM）被用来研究一个特定的识别反应：链霉亲和素的生物素化的脂质双分子层的结合。在识别反应之前，清楚地观察到脂双层的相共存：流体域低于结晶域。在向双层中引入非常稀的链霉亲和素溶液以得到约0.5 μ M的终浓度后，对识别反应进行真实的成像。几个小时后，我们观察到对比度反转，即，先前较低的流体区域在高度上生长得如此之多，以至于它们变得高于结晶区域。我们发现，链霉亲和素分子几乎只与流体域中的生物素结合（< 0.25%的结晶域覆盖率）。结合到双层的结晶域的几个链霉亲和素分子的表观结构示出依赖于所施加的力。最后，在二维准晶体中，链霉亲和素分子在空气-水界面处被压缩，实现了分子分辨率。
An atomic force microscope (AFM) was used to investigate a specific recognition reaction: the binding of streptavidin to a biotinylated lipid bilayer. Prior to the recognition reaction, the phase coexistence of the lipid bilayer was clearly observed: fluid domains were lower than the crystalline domains. After introducing to the bilayer a very dilute solution of streptavidin to give a final concentration of approximately 0.5-mu-M, the recognition reaction was imaged in real time. Several hours later, we observed a contrast reversal, i.e., the previously lower fluid domains grew so much in height that they became higher than the crystalline domains. We found that the streptavidin molecules bound almost exclusively to the biotin in the fluid domain ( < 0.25% coverage of the crystalline domains). The apparent structure of the few streptavidin molecules bound to the crystalline domain of the bilayer is shown to depend on the applied force. Finally, in a 2-dimensional quasi-crystal in which the streptavidin molecules were compressed at the air-water interface molecular resolution was achieved.